Light collecting module

ABSTRACT

A light collecting module includes a pliable light guide, an inner light source, and a photocell. A surface of the light guide has a first area, a second area, and a third area. The first and second areas face each other, and the third area is adjacent to the first or second area. At least one optical structure is formed in the second area, and the photocell is adjacent to the third area. The optical structure is for redirecting ambient light incident on the first or second area such that the ambient light is guided to the third area by refraction or reflection and incident on the photocell. The optical structure is for redirecting the light from the inner light source such that the light is guided to the surface of the light guide by refraction or reflection and exits the light guide.

1. FIELD OF THE INVENTION

The instant disclosure relates to a light collecting module; in particular, to a pliable light collecting module.

2. DESCRIPTION OF RELATED ART

With the rapid development of technology and the economy, increasing fossil fuel depletion and greenhouse gas emission is concerned. For example, the use of oil, natural gas, coal and other polluting energy will lead to increasingly serious environmental damage. Moreover, these polluting energy gradually face to the problem of shortage, steady supply of energy has become a major worldwide issue. Therefore, non-polluting and renewable energy, such as hydro, wind, solar, biomass and other more has become more and more valued.

In recent years, alternative energy and renewable energy technology continue to be developed, and photoelectric conversion technology is the most valued. For example, solar cells can directly convert light energy into electrical energy, and not accompanied by the generation of greenhouse gases or polluting gas such as carbon dioxide, nitrogen oxides and sulfur oxides, which will not pollute the environment, to reduce the dependence on fossil fuels and provide a safe and independent source of electricity.

In order to meet the requirements of the miniaturization in packaging, the circuit board is also gradually evolved by the double-layer circuit board into a multilayer circuit board, thereby expanding the area of wiring available on the circuit board layout in the limited space of the circuit board through the interlayer connection technology.

SUMMARY OF THE INVENTION

The object of the instant disclosure is to provide a light collecting module. The light collecting module utilize at least one optical structure formed in a second area of a surface of a pliable light guide to redirect the ambient light to collect light and to form a surface light source.

The light collecting module includes a pliable light guide, an inner light source, and a photocell. A surface of the light guide has a first area, a second area, and a third area. The first area and the second area face each other, and the third area is adjacent to the first area or the second area. The optical structure is formed in the second area of the surface. The inner light source is connected to the pliable light guide, and the photocell is adjacent to the third area of the surface.

The optical structure is for redirecting ambient light incident on the first or second area of the surface such that the ambient light is guided to the third area by refraction or reflection and incident on the photocell. In addition, the optical structure is for redirecting the light from the inner light source such that the light from the inner light source is guided to the surface of the light guide by refraction or reflection and exits the light guide.

In summary, the light collecting module can redirect and collect the light incident on the surface of the pliable light guide toward the photocell for being optically coupled to the photocell. Meanwhile, the light collecting module can redirect the light from the inner light source to the surface of the light guide and exits the light guide for forming a surface light source.

In order to further understand the instant disclosure, the following embodiments are provided along with illustrations to facilitate the appreciation of the instant disclosure; however, the appended drawings are merely provided for reference and illustration, without any intention to be used for limiting the scope of the instant disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a perspective view of a light collecting module in accordance with an embodiment of the instant disclosure.

FIG. 1B illustrates a side view of a light collecting module in accordance with FIG. 1A.

FIG. 2A is a side enlarged view, partially in area, showing a light collecting module in accordance with FIG. 1A.

FIG. 2B is a side enlarged view, partially in area, showing a light collecting module in accordance with another embodiment of the instant disclosure.

FIG. 2C is a side enlarged view, partially in area, showing a light collecting module in accordance with another embodiment of the instant disclosure.

FIG. 3A illustrates a perspective view of a light collecting module in accordance with another embodiment of the instant disclosure.

FIG. 3B illustrates a side view of a light collecting module in accordance with FIG. 3A.

FIG. 4A illustrates a perspective view of a light collecting module in accordance with another embodiment of the instant disclosure.

FIG. 4B illustrates a top plane view of a light collecting module in accordance with FIG. 4A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The aforementioned illustrations and following detailed descriptions are exemplary for the purpose of further explaining the scope of the instant disclosure. Other objectives and advantages related to the instant disclosure will be illustrated in the subsequent descriptions and appended drawings.

(First Embodiment of a Light Collecting Module).

Please refer to FIGS. 1A, 1B, and 2A. FIG. 1A illustrates a perspective view of a light collecting module in accordance with an embodiment of the instant disclosure, FIG. 1B illustrates a side view of a light collecting module in accordance with FIG. 1A, and FIG. 2A is a side enlarged view, partially in area, showing a light collecting module in accordance with FIG. 1A. The light collecting module includes a pliable light guide, an inner light source, and a photocell. A surface of the light guide has a first area, a second area, and a third area. The first area and the second area face each other, and the third area is adjacent to the first area or the second area. At least one optical structure is formed in the second area of the surface. The inner light source is connected to the pliable light guide, and the photocell is adjacent to the third area of the surface.

The pliable light guide is flexible and made of optically transmissive materials that are transparent to radiation. In the instant embodiment, the pliable light guide may have elongate rectangular shape and measure, for example, 0.1 mm (millimeter) to 50 mm in thickness. In alternate embodiment, the pliable light guide may have a thickness more than 50 mm. An upper surface, a lower surface facing the upper surface, and side surfaces form the surface of the pliable light guide. In other words, the upper surface and the lower surface are bound by the side surfaces. Note that in another embodiment, the pliable light guide may be configured to a great variety of shapes. For example, the pliable light guide may include a wedge plate, or the pliable light guide may be triangular pyramidal or have an irregular shape. The configuration thereof is not limited thereto.

The pliable light guide is optically transmissive and for guiding the light. For example, the refractive index of the pliable light guide can be greater than that of the light propagating medium outside the pliable light guide. Consequently, the light can be guided and propagate within the pliable light guide by total internal reflection. In the instant disclosure, the refractive index of the pliable light guide ranges from 1.0 to 1.85. In addition, the pliable light guide can be made of materials allowing the passage of radiation at one or more specified wavelengths, thereby the pliable light guide is transparent. For example, the pliable light guide can be transparent to the radiation at one or more wavelengths in the range of the visible spectrum. In another exemplary embodiment, the pliable light guide can be transparent to the radiation at one or more wavelengths in the range of the infrared or ultraviolet spectrum. In the instant disclosure, the pliable light guide can be formed from glass, plastic, electrochromic glass, or smart glass. However, the materials for making the pliable light guide are not limited thereto. In an exemplary embodiment, the pliable light guide includes, for example, a flexible board, a plastic board, a reflective board, an acrylic board, a polycarbonate (PC) board, the of polyvinyl chloride (PVC) board, polyethylene (PE) board or a polypropylene (PP) board.

Furthermore, the light guide is pliable. For example, the pliable light guide can be made of flexible materials, including polyesters, polycarbonates, ink, light-activated resin, or optical clear adhesive. To put it concretely, the pliable light guide can be bent, folded, or rolled, or the pliable light guide can be compressed to change the shape thereof. Thereby, depending on the actual needs, the users can make the light collecting module into different forms by bending, folding, rolling or compressing the pliable light guide. As shown in FIG. 1A, the pliable light guide is S-shaped when the light collecting module is in use. However, the instant disclosure is not limited thereto.

The surface of the pliable light guide has the first area, the second area, and the third area. The first area and the second area face each other, and the third area is adjacent to the first area or the second area. As shown in FIG. 1A in the present disclosure, the first area is the part of the upper surface S1 that is adjacent to the side surface S3. The second area is the part of the lower surface S2 that is adjacent to the side surface S3, and the third area is the side surface S3. It is worth to note that the surface of the pliable light guide may have more than one first area, second area, or third area. In the present embodiment, for example, the surface of the pliable light guide may further have the first area, the second area, and the third area.

As shown in FIG. 1A, the first area is the part of the lower surface S2 that is adjacent to the side surface S4. The second area is the part of the upper surface S1 that is adjacent to the side surface S4, and the third area is the side surface S4. It is worth to note that the configurations of the positioning, the shape, or the size of the first area, the second, and the third area may vary with respect to, for example, the shape, the deflection property or the refractive index of the pliable light guide and the instant disclosure is not limited thereto.

A plurality of optical structures parallel to each other are formed in the second area of the surface, and each optical structure is a straight elongate rib projecting inward into the pliable light guide. As shown in FIG. 2A, a cross section of each optical structure is triangular and has an apex angle, which ranges from 20 to 160 degrees. The optical structures are parallel to each other and the immediately adjacent optical structures are separated by lengthwise intervals. The cross section of all optical structures is identical, and the intervals between the immediately adjacent optical structures are identical as well. In an alternate exemplary embodiment, each optical structure is part of an array of the optical structures, and the optical structures are distributed irregularly or periodically in the second area. The cross section of the optical structure can be trapezoidal, semicircular or wavy-shaped, the optical structure can be curved or have non linear extent, and the instant disclosure is not limited thereto. In addition, the configurations of the number, the shape, the size, and the positioning of the optical structure may vary with respect to the actual needs and design requirements, and the optical structures may have different shapes or sizes. For example, in another embodiment, each optical structure can be a rounded projecting bulge, and the optical structure formed in different second areas may alter.

It is worth to note that the optical structures can be distributed irregularly or periodically in each second area. The distribution density of the optical structures in each second area can vary according to the deflection property of the pliable light guide and the configurations of the distribution of the optical structures may vary with respect to the actual needs and design requirements. In an exemplary embodiment, the larger the flexural modulus of the pliable light guide, the greater the distribution density of the optical structures. That is to say the more optical structures are formed in the second area. On the other hand, the less the flexural modulus of the pliable light guide, the less the distribution density of the optical structures. That is to say the less optical structures are formed in the second area. The degree of the apex angle varies with respect to the flexural modulus of the pliable light guide. The apex angle ranges from 20 to 160 degrees, and the apex angle is preferably 120 degrees.

In another embodiment of the disclosure, the optical structures formed in the second area have different sizes. In an exemplary embodiment, the larger the curvature of the pliable light guide when the light collecting module is in use, the greater the size of the optical structures. That is to say the greater the vertical height of the optical structure to the surface. On the other hand, the less the curvature of the pliable light guide when the light collecting module is in use, the less the size of the optical structures. That is to say the less the vertical height of the optical structure to the surface.

Furthermore, the optical structures formed in the single second area may have different sizes with respect to the curvature of different parts of the second area when the light collecting module is in use. To put it in concrete, in an exemplary embodiment, the part of the second area that is adjacent to the third area has a less curvature when the light collecting module is in use. The optical structures formed in the part of the second area adjacent to the third area may have smaller size. On the other hand, the part of the second area that is apart from the third area has a greater curvature when the light collecting module is in use. The optical structures formed in the part of the second area that is apart from the third area may have greater size. However, the instant disclosure is not limited thereto.

Please refer to FIGS. 1A and 1B. The inner light source is connected to the pliable light guide for emitting light. In the present disclosure, the inner light source can be embedded in the pliable light guide. The inner light source can be a point light source and contain a LED. In an alternate embodiment, the inner light source can be a line light source, a surface light source, or other types of light source. The inner light source may contain a laser diode, cold cathode fluorescent lamp (CCFL) or other types of light-emitting element. The inner light source can emit the light directly or indirectly by reflection. Conventional light sources well known to those skilled in the art may be employed and the instant disclosure is not limited thereto.

The pliable light guide can redirect the light from the inner light source such that the light from the inner light source is guided to the first area and exits the light guide, whereby forming a surface light source. To put it in concrete, the light from the inner light source can be guided within the light guide by refraction or reflection and strike the surface in the second area, and the optical structure formed in the second area can change the propagation direction of the light. That is to say the optical structure can redirect the light from the inner light source such that the light from the inner light source is guided to the first area by refraction or reflection and exits the light guide forming the surface light source. In an alternate embodiment, the optical structure may redirect the light from the inner light source such that the light from the inner light source is guided to the other parts of the surface by refraction or reflection and exits the light guide for forming a surface light source. For example, the optical structure may redirect the light from the inner light source such that the light from the inner light source is guided to the second area by refraction or reflection and exits the light guide for forming a surface light source.

In addition, the optical structure can redirect the ambient light, which is from an external light source disposed outside the light collecting module, incident on the first area of the surface such that the ambient light is guided to the third area by refraction or reflection. The external light source can be the natural light source such as the sun or can be a light-emitting device containing a laser diode. As shown in FIGS. 1A and 1B in the present disclosure, the ambient light incident on the first area can propagate within the pliable light guide and be guided to the second area by refraction or reflection. After striking the surface in the second area, the optical structure formed in the second area can change the propagation direction of the light. That is to say the optical structure can redirect the ambient light such that the ambient light is guided to the third area by refraction or reflection. Specifically, the optical structure formed in the second area can change the propagation direction of the ambient light incident on the first area such that the ambient light is guided toward the third area with a small incidence angle so to allow desired luminance efficiency in the third area of the pliable light guide.

Photocell may convert the light energy to other forms of energy. For example, photocell may convert the light energy into electrical energy. Specifically, photocell can generate and support an electric current without being attached to any external voltage source when exposed to light. In the present disclosure, the photocell can be a photovoltaic cell such as photoelectrochemical cell, dye-sensitized solar cell, polymer solar cell, nano-crystalline solar cell or the like. The photocell can be made of semiconductor materials containing monocrystalline silicon, polycrystalline silicon, cadmium telluride (CdTe), copper indium selenide (CIS), copper indium gallium selenide (CIGS), Gallium arsenide (GaAs) and the combination thereof. In another embodiment, the photocell can include a plurality of stacked layers of photovoltaic material. Specifically, the photocell may include a PN junction layer, an electron hole junction layer, a silicon layer, a nano organic layer, a multiple layer of compounds and the combination thereof.

As shown in the FIGS. 1A and 1B in the present disclosure, the photocell is adjacent to the third area of the pliable light guide's surface, and the light guided to the third area can be incident on the photocell to be optically coupled to the photocell. In the instant embodiment, the photocell is disposed around the pliable light guide yet the photocell may be attached to the surface of the pliable light guide. Other configurations of the positioning of the photocell with respect to the pliable light guide are also possible, and the instant disclosure is not limited thereto. It is worth to note that the light collecting module of the instant embodiment can have two photocells adjacent to each third area. In an alternate embodiment, the light collecting module may have more than one photocell adjacent to the single third area.

The light collecting module can further include a reflective layer disposed in the second area. The reflective layer can be a metal deposition layer, a metal film or a metal printing layer, and the reflective layer may contain a high reflectance material such as silver (Ag), aluminum (Al), gold (Au), copper (Cu), palladium (Pd), platinum (Pt), radium (Rd), or the like. When the ambient light incident on the first area strikes the surface in the second area, the ambient light can be guided within the pliable light guide by total internal reflection at the reflective layer in the second area so as to prevent the light from escaping from the pliable light guide plate or to reduce the loss in the guided light, whereby providing highly utilization. As shown in the FIGS. 1A and 1B in the present disclosure, the reflective layer is an organic coating layer containing a high reflectance material. In addition, the reflective layer is a pliable layer. Thereby the reflective layer is not easily peeled off when the light collecting module is in use, specifically, when the pliable light guide is bent to certain shape. The reflective layer preferably measure more than 500 angstrom (A) in thickness and completely covers the surface in the second area. In an alternate embodiment, the reflective layer may have a plurality of dots made of metal thin film ordered distributed in the second area.

In addition, in another embodiment, the light collecting module can be disposed on a display device. To put it in concrete, the display may further include a substrate and a display unit. The light collecting module can be disposed atop the substrate, or the light collecting module can be disposed atop, below, aside, in front of, or within the displaying unit.

(Second Embodiment of a Light Collecting Module).

Attention is now invited to FIG. 2B is a side enlarged view, partially in area, showing a light collecting module in accordance with another embodiment of the instant disclosure. The light collecting module is similar to the aforementioned light collecting module and the description hereinafter further explains the difference there-between.

According to the embodiment, a plurality of the optical structures parallel to each other are formed in the second area of the surface, and each optical structure is a straight elongate groove projecting outward from the pliable light guide. A cross section of each optical structure is triangular, yet the cross section of the optical structure may be trapezoidal, semicircular or wavy shaped in an alternate embodiment. The optical structure can be curved or have non liner extent in another embodiment, and the instant disclosure is not limited thereto.

(Third Embodiment of a Light Collecting Module).

Attention is now invited to FIG. 2C is a side enlarged view, partially in area, showing a light collecting module in accordance with another embodiment of the instant disclosure. The light collecting module is similar to the aforementioned light collecting module and the description hereinafter further explains the difference there-between.

According to the embodiment, a plurality of the optical structures parallel to each other are formed in the second area of the surface, and each optical structure is a printed pattern layer projecting inward into the pliable light guide. For example, the pattern of the optical structures may be formed by an array of rows or columns parallel to each other or may be formed by a matrix composed of rows or columns, or have an irregular shape. The optical structures may be configured to having a great variety of patterns having different orientations and the configuration thereof is not limited thereto. Furthermore, the materials for forming the optical structures are not limited thereto.

(Fourth Embodiment of a Light Collecting Module).

Attention is now invited to FIGS. 3A and 3B, FIG. 3A illustrates a perspective view of a light collecting module in accordance with another embodiment of the instant disclosure, and FIG. 3B illustrates a side view of a light collecting module in accordance with FIG. 3A. The light collecting module is similar to the aforementioned light collecting module and the description hereinafter further explains the difference there-between.

According to the embodiment, as shown in FIGS. 3A and 3B, the inner light source is disposed atop and attached to the upper surface of the pliable light guide. The photocell is disposed on and attached to the surface in the third area. The photocell is electrically connected to the inner light source, whereby the electricity generated by the photocell can be provided to the inner light source. The light collecting module further includes a battery module coupled to the photocell. In an alternate embodiment, the photocell can be disposed within the pliable light guide and electrically connected to the inner light source.

In an exemplary embodiment, the light collecting module may further include an energy accumulator and a switch. The accumulator is electrically connected to the photocell for storing the electrical energy converted from the photocell, and the switch is electrically connected to the accumulator for switching to use the energy stored in the accumulator when the energy stored in the accumulator is below a predetermined level. In addition, the light collecting module may further include a battery and a control circuit. The battery is coupled to the inner light source. When the energy stored in the battery is below a predetermined level, the switch can switch to use the energy stored in the accumulator. When the energy stored in the battery is below a predetermined level, the control circuit can control the light collecting module to recharge the battery.

(Fifth Embodiment of a Light Collecting Module).

Attention is now invited to FIGS. 4A and 4B, FIG. 4A illustrates a perspective view of a light collecting module in accordance with another embodiment of the instant disclosure, and FIG. 4B illustrates a top plane view of a light collecting module in accordance with FIG. 4A. The light collecting module is similar to the aforementioned light collecting module and the description hereinafter further explains the difference there-between.

As shown in FIG. 4A in the instant embodiment, the pliable light guide can be rolled to a cylindrical shape. An inner side surface, an outer side surface, a top surface and a bottom surface form the surface of the pliable light guide. In other words, the inner side surface and the outer side surface are bound by the top surface and the bottom surface. The first area is a part of the outer side surface, and the second area is part of the inner side surface that is facing the first area. The third area is part of outer side surface that is adjacent to the first area. The inner light source is disposed on and attached to the inner side surface, and the photocell embedded in the pliable light guide is adjacent to the third area.

The light from the inner light source incident on the surface can be guided within the pliable light guide toward the second area by refraction or reflection, and the optical structure formed in the second area can change the propagation direction of the light. That is to say the optical structure can redirect the light from the inner light source such that the light from the inner light source is guided to the first area by refraction or reflection and exits the light guide for forming a surface light source.

In addition, the ambient light incident on the first area can propagate within the pliable light guide and be guided to the second area by refraction or reflection. Further, the optical structure formed in the second area can change the propagation direction of the light. That is to say, the optical structure can redirect the ambient light such that the ambient light is guided to the third area with a small incidence angle by refraction or reflection.

As shown in the FIGS. 1A and 1B in the present disclosure, the photocell is adjacent to the third area of the pliable light guide's surface, and the light guided to the third area can be incident on the photocell to be optically coupled to the photocell.

(Possible Effects of an Embodiment of a Light Collecting Module)

According to the embodiment, the light collecting module includes the optical structure so as to change the propagation direction of the light incident on the surface within the pliable light guide, whereby the light guided to the third area can be incident on the photocell and be optically coupled to the photocell. The light collecting module can allow highly amount of the ambient light guided to the third area or optically coupled to the photocell, thereby improving the efficiency of the photocell. In addition, the optical structure formed in the second area may redirect the light from the inner light source to the surface of the light guide and exits the light guide for forming a surface light source.

According to the embodiment, the light collecting module can be bent, folded, or rolled for being disposed on a non-planer surface of a device to fit the external institutional environment. Furthermore, the light collecting module may be configured to a great variety of shapes and the configuration thereof is not limited thereto. For example, with the appearance of the laptop or the Tablet PC, the light collecting module can be realized as a protective sleeve for the laptop or the tablet computer, and the photocell can be a solar cell. Thereby, the light collecting module including the photocell can provide electricity for the laptop or the tablet, or to recharge the computer peripheral accessories.

In other applications, the light collecting module can be disposed on clothing. For example, the light collecting module may allow highly amount of the ambient light optically coupled to the photocell in order to improve the efficiency of the photocell, and the photocell can be a solar cell. The light collecting module including the photocell can provide electricity for handheld devices such as PDAs, mp3 player, mobile phone, etc. Meanwhile, the electrical energy generated by the photocells can be provided to the inner light source, thereby forming the surface light source so as to illuminate in the dark. For example, the light collecting module can be disposed on vests and jackets worn by airline ground staff, police, firefighters and emergency workers, to illuminate in the dark to enhance visibility.

The descriptions illustrated supra set forth simply the preferred embodiments of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alternations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims. 

What is claimed is:
 1. A light collecting module comprising: a pliable light guide, a surface of the light guide having a first area, a second area, and a third area, wherein the first area and the second area are facing each other, the third area is adjacent to the first or second area, and the surface has at least one optical structure formed in the second area; an inner light source for emitting light, wherein the inner light source is connected to the pliable light guide, wherein the optical structure is for redirecting the light from the inner light source such that the light from the inner light source is guided to the surface of the light guide by refraction or reflection and exits the light guide; and a photocell adjacent to the third area of the surface, wherein the optical structure is for redirecting ambient light incident on the first or second area of the surface such that the ambient light is guided to the third area by refraction or reflection and incident on the photocell.
 2. The light collecting module according to claim 1, wherein the pliable light guide comprises a wedge plate.
 3. The light collecting module according to claim 1, wherein the refractive index of the pliable light guide ranges from 1.0 to 1.85.
 4. The light collecting module according to claim 1, wherein the optical structure is for redirecting the light from the inner light source such that the light from the inner light source is guided to the first area or second area by refraction or reflection.
 5. The light collecting module according to claim 1, wherein the optical structure comprises a projecting bulge, a projecting rib, a groove, or a printed pattern layer.
 6. The light collecting module according to claim 1, wherein a cross section of the optical structure is triangular, trapezoidal, semicircular or wavy shaped.
 7. The light collecting module according to claim 1, wherein the optical structure is part of an array of the optical structures, and the optical structures are distributed irregularly or periodically in the second area.
 8. The light collecting module according to claim 1, wherein the photocell is attached to the surface of the pliable light guide.
 9. The light collecting module according to claim 1, wherein the photocell is disposed within the pliable light guide and is electrically connected to the inner light source.
 10. The light collecting module according to claim 1, further comprising a reflective layer disposed in the second area.
 11. The light collecting module according to claim 1, wherein further comprising a battery module coupled to the photocell.
 12. The light collecting module according to claim 1, wherein the photocell comprises a plurality of stacked layers of photovoltaic material.
 13. The light collecting module according to claim 1, wherein the photocell comprises a PN junction layer, an electron hole junction layer, a silicon layer, a nano organic layer or a multilayer of compounds.
 14. The light collecting module according to claim 1, wherein the pliable light guide comprises a flexible board, a plastic board, a reflective board, an acrylic board, a polycarbonate board, a polyvinyl chloride board, a polyethylene board or a polypropylene board.
 15. The light collecting module according to claim 1, further comprising an energy accumulator and a switch, the accumulator electrically connected to the photocell for storing the electrical energy converted from the photocell, the switch electrically connected to the accumulator for switching to use the energy stored in the accumulator when the energy stored in the accumulator is below a predetermined level.
 16. The light collecting module according to claim 15, further comprising a battery electrically connected to the inner light source, wherein the switch switches to use the energy stored in the accumulator when the energy stored in the battery is below a predetermined level.
 17. The light collecting module according to claim 16, further comprising a control circuit for controlling the light collecting module to recharge the battery when the energy stored in the battery is below a predetermined level.
 18. A display device comprising: a substrate; a displaying unit; and a light collecting module disposed atop the substrate, or the light collecting module disposed atop, below, aside, in front of, or within the displaying unit, the light collecting module comprising: a pliable light guide, a surface of the light guide having a first area, a second area, and a third area, wherein the first area and the second area are facing each other, the third area is adjacent to the first or second area, and the surface has at least one optical structure formed in the second area; and an inner light source for emitting light, wherein the inner light source is connected to the pliable light guide.
 19. The display device according to claim 18, further comprising a photocell adjacent to the third area of the surface, wherein the optical structure is for redirecting ambient light incident on the first or second area of the surface such that the ambient light is guided to the third area by refraction or reflection and incident on the photocell, and the optical structure is for redirecting the light from the inner light source such that the light from the inner light source is guided to the surface of the light guide by refraction or reflection and exits the light guide. 